udev is slow to start at boot time
You are compiling your kernel yourself or after a kernel update from your distribution, udev takes forever to start but you don't know why. I will give you the solution to this problem in this post.
The solution is actually really simple. udev has problems when deprecated sysfs is enabled so you just need to remove it from your kernel configuration:
#CONFIG_SYSFS_DEPRECATED is not set
#CONFIG_SYSFS_DEPRECATED_V2 is not set
If you are using make menuconfig then it's in General setup:
[ ] enable deprecated sysfs features which may confuse old userspace tools